Monday, March 14, 2016

Red light cameras: About safety or money?

I saw your comment on the Hoodline article and thought you might like to know about this.

Last August the SFMTA staff which operates The City's 41 red light cameras looked at the effect the nineteen-year-old program has had upon the incidence of broadside crashes with injury. While their 28 page report (copy attached) leads off with an impressive looking graph (Fig. 1) showing a dramatic decrease in crashes citywide*, the intersection-by-intersection charts for just the intersections having red light cameras (Figs. 2 thru 26) tell a very different story: At the vast majority of those intersections, the red light camera(s) clearly had no beneficial effect. Instead, the times when crashes dropped coincided with changes like making the yellows longer, adding an all-red interval (both of which are cheap to do), the addition of an arrow for left turns, or a general upgrade to the signal. (Another measure that reduces running is having large "backplates" on the signals, so that the lights stand out from the background. Backplates should be SOP in San Francisco, even on Market Street.)

*Note: The citywide graph (Fig. 1) covers only 1999 to 2011, while the notes above it say: "Red light running collisions have shown a general decrease since the early 1990's...."---well before the program began. (Emphasis added.)

I got my copy of the report because it was finalized about the same time I submitted a routine public records request for a copy of The City's "annual report" about the camera program. (The annual reporting is required by a 2013 California law; but most cities produce a report of just one page.) Even though the report was finished six months ago, as of last month the report had not been published on the SFMTA website nor had it been distributed to the SFMTA board.